Odds of Hay Fever Up With Very Early, Late Spring Onset

Odds of hay fever increased for start of season more than three weeks before or after normal onset

THURSDAY, April 4, 2019 (HealthDay News) -- Very early onset and late onset of spring are associated with increased odds of hay fever, according to a study published online March 28 in PLOS ONE.

Amir Sapkota, Ph.D., from the University of Maryland in College Park, and colleagues examined whether early onset of spring is associated with increased hay fever burden. The median cardinal date for start of season (SOS) was calculated for each county within the contiguous United States for 2001 to 2013. Yearly deviations in SOS were categorized from their respective long-term averages as very early (more than three weeks early), early (one to three weeks early), average (within one week), late (one to three weeks late), and very late (more than three weeks late). These data were linked to data from the National Health Interview Survey for hay fever prevalence in 2002 to 2013.

The researchers found that the odds of hay fever were increased for adults living in counties with a very early onset of SOS compared with the reference group, where onset of spring was within the normal range (odds ratio, 1.14). Adults living in counties with very late onset of SOS also had increased odds of hay fever (odds ratio, 1.18).

These results "confirm a clear link between floral phenology and allergenic disease that is perturbed by climate change," the authors write.